This application incorporates by reference of Taiwan application Ser. No. 090207391, filed May 7, 2001.
1. Field of the Invention
The invention relates in general to a wiper for cleaning the nozzle surface, and more particularly to a wiper for avoiding ink residues on side surfaces of the print head.
2. Description of the Related Art
In the technology booming age, the ink-jet machine, such as the ink-jet printer or inkjet copier, has grown in popularity and thus becomes indispensable for people""s life. For example, the ink-jet printer is capable of printing the document by linking the ink-jet printer and the computer so as to improve work efficiency.
The ink required by the ink-jet machine is contained in the cartridge while the print head is positioned at the bottom of the cartridge. The print head jets small ink droplets onto the paper through the nozzle surface of the print head to create an output image. Accordingly, the ink residues adhere to the nozzle surface. If the ink residues are accumulated without cleaning, the dried ink residues are possible to form blockages in the print head or smudge the paper, which might decrease the printing quality. Therefore, the printing work shall be halted for wiping the ink residues on the nozzle surface in the cleaning area inside the ink-jet machine whenever the printing has performed several times. The following description takes an ink-jet printer as an example of the ink-jet machine.
Referring to FIG. 1A, it shows the top view of a conventional ink-jet printer. The ink-jet printer 100 comprises a casing 101, print head 102, and cleaning area 106. The print head 102 inside the casing 101 is driven by a driving device (not shown in FIGS) and moves back and forth on the paper to be printed 104 along the direction of the arrow sign 150 of FIG. 1A. The print head 102 jets ink droplets onto the paper to be printed 104 and the paper to be printed 104 moves upward along the direction of the arrow sign 160 of FIG. 1A to complete the printing work. The cleaning area 106 includes a wiper, cap, and blotter. The wiper is for wiping the ink residues on the surface of the print head 102. The cap is the cover of the print head 102 for preventing the ink from being dried to form blockages in the print head 102 while the print head is homed at the cleaning area 106. The blotter is for blotting out the ink splashed during the cleaning.
The structure of the wiper 130 in the cleaning area 106 is disclosed in U.S. Pat. No. 5,612,722 by Monty L. Francis, Edmund H. James, III, and Donald N. Spitz. Lateral views of the print head and the wiper of FIG. 1A are shown in FIG. 1B. The wiper 130 includes a main body 108 and a base 118. The main body 108 has a supporting portion 109, flexible portion 112, and wiping portion 114. The supporting portion 109 has a groove 116 for the insertion of the protruding end 115 of the supporting portion 109 so that the main body 108 can be mounted on the base 118. The flexible portion 112 is disposed upon the supporting portion 109, the wiping portion 114 is upon the flexible portion, and therefore the supporting portion 109, flexible portion 112, and wiping portion 114 are in one unity.
Please refer to FIG. 1C, the enlarged view of the wiping portion 114 of FIG. 1B is shown. The wiping portion 114 has a coplanar surface 120, wiping ends 122a and 122b. The wiping ends 122a and 122b are disposed at two sides of the coplanar surface 120 and form two acute angles respectively. The coplanar surface 120 is level with the wiping ends 122a and 122b. Besides, the plane formed by the coplanar surface 120 and the wiping ends 122a and 122b is higher than the plane level L of the nozzle surface 110. When the wiper 130 is stationary and the print head 102 moves back and forth along the direction of the arrow sign 170 of FIG. 1B, the wiping ends 122a and 122b contact the side surfaces 102a and 102b of the print head 102 respectively. The flexible portion 112 bends down while the print head 102 pushes the wiping portion 114. The wiping ends 122a and 122b touches the nozzle surface 110 and then the ink residues on the nozzle surface 110 is removed as the relative motion between the print head 102 and the wiper 130 proceeds.
Referring to FIGS. 2A to 2G, it schematically illustrates the wiping sequences of the wiper of FIG. 1B for wiping the ink residues. Referring first to FIG. 2A, as the print head 102 approaches the wiping end 122a along the direction of the arrow sign 180 of FIG. 2A, the side surface 102a of the print head 102 subsequently touches and pushes the wiping end 122a so that the flexible portion 112 bends to the right. As shown in FIG. 2B, the print head 102 proceeds to move along the direction of the arrow sign 180 of FIG. 2B. Subsequently, the wiping end 122a touches the nozzle surfaces 110 and removes the ink residue 111 as the relative motion between the print head 102 and the wiping end 122a proceeds. Referring to FIG. 2C, the wiping end 122a comes off the nozzle surface 110 and the ink residue 111 adheres to the left side of the wiping end 122a. Meanwhile, the flexible portion 112 recovers to the former shape and the plane formed by the coplanar surface 120 and the wiping ends 122a and 122b is higher than the plane level L of the nozzle surface L again.
On the other hand, when the print head 102 approaches the wiping end 122b along the direction of the arrow sign 190 of FIG. 2C, the side surface 102b of the print head 102 subsequently touches and pushes the wiping end 122b so that the flexible portion 112 bends to the left as shown in FIG. 2D. The print head 102 proceeds to move along the direction of the arrow sign 190 of FIG. 2D and the wiping end 122b subsequently touches the nozzle surfaces 110 and performs wiping. Once the wiping end 122b comes off the nozzle surface 110, the flexible portion 112 recovers to the former shape and the ink residue 111 remains adhering to the left side of the wiping end 122a as shown in FIG. 2E. At this time, if the print head 102 approaches the wiping end 122a along the direction of the arrow sign 180 of FIG. 2E again, the side surface 102a of the print head 102 subsequently touches the wiping end 122a and the ink residue 111 as shown in FIG. 2F As shown in FIG. 2G, the ink residue 111 is shifted from the left side of the wiping end 122a to the side surface 102a of the print head 102.
Conventionally, the wiping ends 122a and 122b of the main body 108 are two sides of the coplanar surface 120. The coplanar surface 120 is level with the wiping ends 122a and 122b and the wiping force is generated by the deformation of the main body 108 due to the relative motion between the print head 102 and the wiping ends 122a and 122b. The ink residue 111 on the nozzle surface 110 is removed by the wiping end 122a and 122b and finally adheres to the side surface 102a and 102b of the print head 102. Consequently, when the cleaning completes and the print head 102 proceeds to print, the ink residue 111 adheres to the side surface 102a and 102b of the print head 102 might fall to the paper to be printed 104. The paper is smudged with the ink residues and the printing quality is therefore decreased.
It is therefore an object of the invention to provide a wiper for avoiding ink residues on side surfaces of the print head. It keeps side surfaces of the print head clean and ensures the printing quality.
The invention achieves the above-identified objects by providing a wiper for avoiding ink residues on side surfaces of a print head, the wiper comprises a main body and a base. The main body comprises a supporting portion, flexible piece, and wiping portion. The flexible piece is disposed upon the supporting portion and the wiping portion is disposed upon the flexible piece. The wiping portion has a wiping end and a contacting end. The wiping end extends from one side of the wiping portion while the contacting end is positioned on the top of the wiping portion. Before the print head contacts the contacting end, the contacting end is higher than the nozzle surface and the wiping end is lower than the nozzle surface. After the print head contacts the contacting end, the flexible piece bends down due to the relative motion between the print head and the wiper so that the contacting end is lower than the nozzle surface and the wiping end contacts the nozzle surface for wiping the ink residue on the nozzle surface.
Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings.